基于BSR-Seq分析筛选Y1499条锈病抗性相关基因

条锈病是危害小麦生产安全的重要病害之一,而携带不同抗病基因小麦品种的利用与合理布局是降低病害威胁最经济可靠的途径。为挖掘和丰富小麦条锈病抗性相关基因资源,本研究以筛选到的抗条锈病硬粒小麦种质Y1499和感病材料Gaza为亲本构建遗传群体,在室内对其进行苗期抗性鉴定和统计分析;利用衍生后代中选择的F 3∶4群体构建混池,进行RNA测序,对测序数据进行相关分析。结果表明,Y1499对CYR32的抗性由两个主效基因互补遗传控制。利用BSR-Seq关联分析在鉴定到3个小麦材料Y1499中条锈病抗性基因候选区间。GO富集结果显示,F 3∶4抗感池间差异表达基因涉及多个过氧化物酶等抗氧化反应相关基因。KEGG富集结果表明,显著差异表达基因主要富集于谷胱甘肽代谢和苯丙烷类生物合成等代谢通路。

利用BSR-Seq定位小麦品种郑麦103抗条锈病基因YrZM103

郑麦103是一个高抗条锈病的小麦新品种,为明确其携带的抗病基因,用郑麦103与感条锈病品种农大399杂交构建分离群体,用条锈菌CYR32、CYR33和CRY34(V26)混合菌系进行田间接种和成株期抗性鉴定,对214个F2:3家系的条锈病抗性进行遗传分析,初步确定郑麦103的抗条锈性由单个主效基因控制,定名为Yr ZM103。通过BSR-Seq技术开发了6个与Yr ZM103紧密连锁的分子标记,将Yr ZM103定位于染色体臂7BL分子标记ZM215和ZM221之间,遗传距离分别为11.8 c M和6.9 c M。利用7BL染色体上与其他已知抗条锈病基因紧密连锁的分子标记进行比较作图,发现Yr ZM103是不同于7BL末端其他抗条锈病基因的新基因。

Mapping stripe rust resistance genes by BSR-Seq:YrMM58 and YrHY1 on chromosome 2AS in Chinese wheat lines Mengmai 58 and Huaiyang 1 are Yr17

Stripe rust(yellow rust), caused by Puccinia striiformis f. sp. tritici(PST),is one of the most devastating fungal diseases in common wheat(Triticum aestivum L.) in China and worldwide. Resistance breeding is the most effective strategy to control diseases in crop plants. Chinese wheat lines Mengmai 58 and Huaiyang 1 are highly resistant to PST race CYR34(V26) at the adult plant stage. To genetically map the underlying resistance genes we developed segregating populations by crossing Mengmai 58 and Huaiyang 1 with the susceptible cultivar Nongda 399. The stripe rust resistances in Mengmai 58 and Huaiyang 1 were both controlled by single dominant genes, provisionally designated YrMM58 and YrHY1, respectively. Bulked segregant RNA-Seq(BSR-Seq) analysis showed that YrMM58 and YrHY1 were located in the same distal ~16 Mb region on chromosome 2 AS.Comparative genomics analysis with the physical map of Aegilops tauschii proved useful for developing additional markers to saturate the genetic linkage map. YrMM58 and YrHY1 were mapped to the distal end of chromosome arm 2 AS, with the closest marker WGGB148 being 7.7 cM and 3.8 cM from the resistance gene, which was considered to be Yr17. These markers can be used in marker-assisted selection.

基于BSR-Seq对甘蔗脱叶性的研究和生物信息学分析

甘蔗的叶片是制糖过程中杂质的主要来源,育种过程中倾向于选育易脱叶的品种。为了研究甘蔗脱叶性相关的主效、稳定基因,本研究采用BSR-Seq技术,从‘ROC25’ב云蔗89-7’的F1后代中选取极端难脱叶品系和极端易脱叶品系的+6叶位叶鞘离区,分别构建混池,并和亲本一起进行RNA转录组测序分析,共得到60.46Gb的有效片段,4个样品的Q30值均在93%以上,GC含量都大于51%,与参考基因组R570比对,比对率都超过41%。4个样品共检测出4085个差异基因,候选区域定位于9号染色体上的4个位置,总长1.40 Mb,注释到基因86个,亲本间注释到的非同义突变15个,挖掘出2个主效差异基因(Sh09_g020620,Sh09_g020080),Sh09_g020080在亲本的表达差异和子代中是同向的,而Sh09_g020620在2个亲本和2个子代混池之间的差异是异向的,表明可能仅Sh09_g020080对易脱叶性有所贡献。选取BSR亚群体中极端易脱叶品系40-159和极端难脱叶品系5-94的+1~+7叶进行荧光定量分析,发现Sh09_g020080基因在单一品系的表达和子代混池的+6叶的表达是同向的。取另一个‘B35-9’בCP08-1553’的杂交后代个体中的极端易脱叶品系16-226和极端难脱叶品系16-224的+1~+7叶位的叶鞘离区进行荧光定量分析,结果显示Sh09_g020080在2个群体中+4、+5、+6叶位的表达都为易脱叶的品系高于难脱叶品系。注释显示Sh09_g020080具有σ因子活性,参与红光、远红光、蓝光反应。根据理化性质和蛋白质结构,推测Sh09_g020080编码蛋白具有4个保守区域,且具有积累叶绿素的作用。该研究为甘蔗脱叶相关主效候选基因的挖掘提出了新的见解。

Genetic dissection of the powdery mildew resistance in wheat breeding line LS5082 using BSR-Seq

Powdery mildew of wheat is a destructive disease seriously threatening yield and quality worldwide.Comprehensive dissection of new resistance-related loci/genes is necessary to control this disease.LS5082 is a Chinese wheat breeding line with resistance to powdery mildew.Genetic analysis,using the populations of LS5082 and three susceptible parents(Shannong 29,Shimai 22 and Huixianhong),indicated that a single dominant gene,tentatively designated PmLS5082,conferred seedling resistance to different Blumeria graminis f.sp.tritici(Bgt)isolates.Bulked segregant RNA-Seq was carried out to map PmLS5082 and to profile differentially expressed genes associated with PmLS5082.PmLS5082 was mapped to a 0.7 cM genetic interval on chromosome arm 2BL,which was aligned to a 0.7 Mb physical interval of 710.3–711.0 Mb.PmLS5082 differs from the known powdery mildew(Pm)resistance genes on chromosome arm 2BL based on their origin,chromosome positions and/or resistance spectrum,suggesting PmLS5082 is most likely a new Pm gene/allele.Through clusters of orthologous groups and kyoto encyclopedia of genes and genomes analyses,differentially expressed genes(DEGs)associated with PmLS5082 were profiled.Six DEGs in the PmLS5082 interval were confirmed to be associated with PmLS5082 via qPCR analysis,using an additional set of wheat samples and time-course analysis postinoculation with Bgt isolate E09.Ten closely linked markers,including two kompetitive allele-specific PCR markers,were confirmed to be suitable for marker-assisted selection of PmLS5082 in different genetic backgrounds,thus can be used to detect PmLS5082 and pyramid it with other genes in breeding programs.

小麦农家品种武都白茧儿抗条锈病基因遗传定位

小麦条锈病是由条形柄锈菌(Pst,Puccinia striiformis f.sp.tritici)引起的一种全球性重要真菌病害,严重影响小麦生产安全。发掘抗病基因,培育抗病品种是防治条锈病最为经济有效和安全的方法。武都白茧儿是甘肃陇南小麦农家品种,在整个生育期都表现出中到高抗条锈病,但其抗性基因尚不明晰。为解析武都白茧儿的条锈病抗性遗传机制,本研究利用抗病亲本武都白茧儿和感病亲本辉县红配制杂交组合,利用条锈菌生理小种V31/lab对其F2和F2:3群体进行苗期接种鉴定,结合混池测序和连锁分析定位抗性基因。结果表明,武都白茧儿对V31/lab抗性由一对隐性基因控制,暂命名为yrWUD。根据F2群体的混池外显子捕获测序和混池转录组测序结果,开发了12个高通量的KASP标记;通过连锁分析,将yrWUD定位在4AL染色体的2.6 cM遗传区间内,与侧翼标记4AL36和4AL11的遗传距离分别为0.9 cM和1.7 cM,对应13 Mb的物理区间(4A:610.26~623.35 Mb),其中3个抗病相关基因TraesCS4A02G329100、TraesCS4A02G330000和TraesCS4A02G330100在抗感池中差异表达,推测为yrWUD的候选基因。本研究定位了武都白茧儿的抗性基因yrWUD,用KASP标记4AL36在自然群体中检测了该基因的等位基因,研究结果为小麦抗条锈病育种提供了新基因和分子标记。

Fine mapping of the powdery mildew resistance gene PmXQ-0508 in bread wheat

In a wheat breeding line XQ-0508 showing consistent resistance to powdery mildew disease,a recessive gene,designated PmXQ-0508,was identified and mapped to a distal region on chromosome arm 2BS.Of three resistance-associated genes in this region,one encoding a protein kinase was selected as the primary candidate for PmXQ-0508.Ten closely linked DNA markers developed in the study could be used for marker-assisted selection for powdery-mildew resistance in breeding programs.

Identification of an Aux/IAA regulator for flesh firmness using combined GWAS and bulked segregant RNA-Seq analysis in watermelon

Watermelon is a highly cultivated fruit crop renowned for its quality properties of fruit flesh.Among various quality factors,fruit flesh firmness is a crucial quality parameter influencing the fruit texture,shelf life and its commercial value.The auxin/indole-3-acetic acid(Aux/IAA)plays a significant role in fruit development and ripening of non-climacteric fruits.However,the regulatory mechanism of Aux/IAA in controlling fruit flesh firmness and ripening in watermelon remains unknown.In this study,we employed an integrative approach combining genome-wide association study(GWAS)and bulked segregant RNA-Seq analysis(BSR-Seq)to identify an overlapping candidate region between 12776310 and 12968331 bp on chromosome 6,underlying an auxin-responsive gene(Aux/IAA)associated with flesh firmness in watermelon.Transcriptome analysis,followed by real-time quantitative reverse transcription PCR(qRT-PCR),confirmed that the expression of Aux/IAA was consistently higher in fruits with high flesh firmness.The sequence alignment revealed a single base mutation in the coding region of Aux/IAA.Furthermore,the concomitant Kompetitive/Competitive allele-specific PCR(KASP)genotyping data sets for F2 population and germplasm accessions identified Aux/IAA as a strong candidate gene associated with flesh firmness.Aux/IAA was enriched in the plant hormone signal transduction pathway,involving cell enlargement and leading to low flesh firmness.We determined the higher accumulation of abscisic acid(ABA)in fruits with low flesh firmness than hard flesh.Moreover,overexpression of Aux/IAA induced higher flesh firmness with an increased number of fruit flesh cells while reducing ABA content and flesh cell sizes.Additionally,the allelic variation in Aux/IAA for soft flesh firmness was found to exist in Citrullus mucosospermus and gradually fixed into Citrullus lanatus during domestication,indicating that soft flesh firmness was a domesticated trait.These findings significantly enhanced our understanding of watermelon fruit flesh firmness and consequently the watermelon fruit quality.

BULKED SEGREGANT RNA SEQUENCING(BSR-SEQ)IDENTIFIES A NOVEL ALLELE ASSOCIATED WITH WEEPING TRAITS IN PRUNUS MUME

Weeping species are used both as ornamental plants and for breeding dwarf plant types.However,exploration of casual genes controlling weeping traits is rather limited.Here,we identified individuals with contrasting phenotypes from an Fx bi-parental mapping population of Prunus mume which was developed from a cross between the upright cultivar/Liuban,and the weeping cultivar'Fentai Chuizhi'.Bulked segregant RNA sequencing was used and five QTLs on chromosome 7 were identified.The Pm024074(PmilGT72B3)allele,belonging to the UDP-glycosyltransferase superfamily containing the coniferyl-alcohol glucosyltransferase domain,was identified in a genomic region overlapping with a previously identified QTL;and had a synonymous transition of T66(upright)to C(weeping)in the coding sequence and a 470-bp deletion in the promoter region.Pm024074 had exceptionally high expression in buds and stems of weeping P.mume.Weighted correlation network analysis indicates that genes neighboring Pm024074 were significantly associated with plant architecture.In addition,a reliable single nucleotide polymorphism marker was developed based on the variation in the Pm024074 gene,providing precise marker-assisted breeding for weeping traits.This study provides insights into the genetic mechanism governing the weeping trait in P.mume,and indicates potential applications for the manipulation of tree architecture.

SlGH9-15 regulates tomato fruit cracking with hormonal and abiotic stress responsiveness cis-elements

Fruit cracking occurs easily during the late period of fruit development when plants encounter an unsuitable environment,dramatically affecting fruit production and marketing.This study conducted the bulked segregant RNA-Seq(BSR)to identify the key regulatory gene of fruit cracking in tomatoes.BSR-Seq analysis illustrated that two regions associated with irregularly cracking were located on chromosomes 9 and 11,containing 127 candidate genes.Further,through differentially expression analysis and qRT-PCR in cracking-susceptible and cracking-resistant genotypes,the candidate gene SlGH9-15(Solyc09g010210)with significantly differential expression levels was screened.Bioinformatics analysis of the GH9 gene family revealed that 20 SlGH9 genes were divided into three groups.The phylogenetic analysis showed that SlGH9-15 was closely related to cell wall construction-associated genes AtGH9B1,AtGH9B6,OsGH9B1,and OsGH9B3.The cis-acting elements analysis revealed that Sl GH9-15 was activated by various hormones(ethylene and ABA)and abiotic stresses.The expression pattern indicated that 13 SlGH9 genes,especially SlGH9-15,were highly expressed in the cracking-susceptible genotype.Its expression level gradually increased during fruit development and achieved maximum value at the red ripe stage.Additionally,the cracking-susceptible tomato showed higher cellulase activity and lower cellulose content than the cracking-resistant tomato,particularly at the red ripe stage.This study identified SlGH9-15 as a key gene associated with fruit cracking in tomatoes for the first time and gives new insights for understanding the molecular mechanism and complex regulatory network of fruit cracking.

玉米黄绿叶突变体表型鉴定及基因初步定位

叶色突变体是研究光合作用及叶绿体发育的重要材料。开展玉米叶色突变体的相关研究,对光形态建成、光合作用、基因功能注释、蛋白质功能及抗逆性机制的阐述具有重要的理论意义。本研究以黄绿叶突变体ygl-F17138为材料,与玉米自交系B73进行杂交,构建F2分离群体,进行遗传效应分析和基因初步定位。遗传分析表明,该突变性状由单个隐性核基因控制,且能稳定遗传。利用BSR-seq结合连锁分析的方法将该基因初步定位在第3条染色体上一个约9.2 Mb的区间内(chr.3:173087201~182203992),查询该区间内已知基因功能注释,未发现类似前人报道的调控黄绿叶性状基因,说明YGL-F17138基因可能是一个控制玉米黄绿叶发育未被挖掘的候选基因。

小麦剩余杂合体株高的基因定位

为挖掘小麦矮秆基因,以矮秆小麦品种品冬34和高秆小麦品种Warran杂交构建的重组自交系(RIL)群体为材料,于F7:8筛选出一个株高性状分离的剩余杂合体。利用BSR-seq技术对该剩余杂合体分离的高株与矮株纯系分别混池测序,进行株高位点的初步定位。结果表明,与株高性状相关的候选区域位于7B染色体687~689 Mb处,该区段内有18个候选基因。其中,TraesCS7B02G419700和TraesCS7B02G420400既参与代谢过程,又参与小麦茎的生长发育;而TraesCS7B02G418900、TraesCS7B02G419000、TraesCS7B02G419600和TraesCS7B02G420000虽在茎中表达,却未参与相关代谢过程。这6个基因特别是TraesCS7B02G419000和TraesCS7B02G420400可作为调控株高性状的候选基因进行深入研究。

小麦高效转基因受体品系CB037的抗条锈性分析

小麦遗传转化是开展小麦基因克隆、基因编辑及基因工程等研究的重要基础。获得易于转化及遗传背景纯合的受体材料是高效开展小麦遗传转化的关键。近年来,小麦品系CB037作为受体材料被广泛利用,并获得了较高的转化效率,在小麦研究中发挥了重要作用。虽然野生型CB037农艺性状整齐一致,但遗传背景并不纯合,对小麦条锈菌(Puccinia striiformis f.sp.tritici)表现高感和高抗两种不同反应。本研究分离了抗病株系CB037-PstR及感病株系CB037-PstS,并创建了F2分离群体。遗传分析表明,CB037-PstR携带单个显性抗病基因。利用BSR-Seq测序分析及分子标记检测,将抗病位点定位于1B染色体短臂。进一步荧光原位杂交表明,CB037-PstR为1BL/1RS易位系,可能携带抗条锈病基因Yr9。本研究明确了CB037的遗传背景及其抗条锈性,并分离了抗病及感病株系,为有效利用CB037作为受体材料开展小麦转基因研究奠定基础。

Identification of a locus associated with genic male sterility in maize via EMS mutagenesis and bulked-segregant RNA-seq

Genic male sterility(GMS) is one of the most important resources for exploiting heterosis in crop breeding, so that identifying genomic loci regulating GMS is desirable. However, many regulatory genes controlling GMS have not yet been characterized in maize, owing partly to a lack of genetic materials. We generated a recessive male-sterile maize mutant in the Jing 724 genetic background via ethyl methanesulfonate treatment, and found the male sterility to be due to a single gene mutation. Bulk-segregant RNA sequencing of three replicates indicated that one genomic region located at the end of chromosome 4 was associated with the observed mutant phenotype. Among genes with nonsynonymous mutations,Zm00001 d053895(bHLH51) showed abolished expression in the sterile bulks and was annotated as a bHLH transcription factor orthologous to Arabidopsis AMS, suggesting an association with the male sterility of the mutant. Kompetitive Allele-Specific PCR assays further validated the exclusive correlation of male sterility with the single C-to-T mutation in the fifth exon. The new maize mutant and the potential SNP locus provide novel genetic material for investigating the molecular mechanism underlying tapetal development and may facilitate the improvement of hybrid production systems.

A 36 Mb terminal deletion of chromosome 2BL is responsible for a wheat semi-dwarf mutation

Reduced plant height is one of the most important traits related to lodging resistance and crop yield. The use of reduced height genes has been one of the main features in breeding modern high-yielding wheat varieties with less lodging. A spontaneous dwarf mutant DD399 was identified in a high yielding, gibberellic acid(GA)-insensitive, lodging-resistant variety Nongda 399(ND399). Significant differences in upper internode lengths between mutant DD399 and wild type ND399 were caused by reduced cell elongation. The plant height of ND399 × DD399 F_(1) hybrids was intermediate between the parents, indicating incomplete dominance or a dose–response effect of a reduced height gene. Plant height showed continuous distribution in the F_(2) population, and segregation distortion was observed among the 2292 F_(2:3) progenies. The reduced height mutation was characterized by Illumina 90 K iSelect SNP genotyping and bulked segregant RNA-Seq(BSR-Seq) analysis of the segregating population. A concentrated cluster of polymorphic SNPs associated with the reduced height phenotype was detected in the distal region of chromosome arm 2 BL. Co-segregation of reduced height phenotype with the clustered markers revealed a 36 Mb terminal deletion of chromosome 2 BL in mutant DD399.

Rapid Identification of a Candidate Gene Related to Fiber Strength Using a Superior Chromosome Segment Substitution Line from Gossypium hirsutum × Gossypium barbadense via Bulked Segregant RNA-Sequencing

Cotton is the most widely cultivated commercial crop producing natural fiber around the world.As a critical trait for fiber quality,fiber strength principally determined during the secondary wall thickening period.Based on the developed BC5F3:5 CSSLs(chromosome segment substitution lines)from Gossypium hirsutum CCRI36×G.barbadense Hai 1,the superior MBI9915 was chosen to construct the secondary segregated population BC7F2 with its recurrent parent CCRI36,which was subsequently subjected to Bulk segregant RNA-sequencing(BSR-seq)for rapid identification of candidate genes related to fiber strength.A total of 4 fiber-transcriptome libraries were separately constructed and sequenced,including two parents(CCRI36 and MBI9915)and two extreme pools at 20 DPA(days post anathesis).Through multiple comparisons,536 DEGs(differentially expressed genes)were overlapped at 20 DPA.Allelic-polymorphism comparison in mRNA sequences revealed 831 highly probable SNPs between two extreme pools related to fiber strength.Linkage analysis was performed between two extreme pools with SNP-index method.Eighteen correlated regions with 1981 annotation genes were obtained between two pools at 20 DPA,of which 12 common DEGs were similarly identified both between two parents and two pools.One gene(Gh_A07G0837)in the candidate region related to fiber strength was differentially expressed in both parents and extreme pools and involved in fiber strength development through reactive oxygen species(ROS)activity.Co-expression analysis of Gh_A07G0837 showed that Gh_A07G0837 may cooperate with other genes to regulate fiber strength.The reliability of BSR-seq results was validated by the quantitative real-time PCR(qRT-PCR)experiments on 5 common DGEs 20 DPA.Co-expressed analysis results indicated that there were some genes expressed especially low in MBI9915,resulting in good fiber strength.Focusing on bulked segregant analysis on the extreme pools derived from superior CSSL population,this study indicates that BSR-seq can be efficiently applied on rapid identification of candidate genes related to fiber strength,which make contributions to our understanding of fiber quality formation in cotton.

玉米类病斑突变体Lmm18的表型与初定位分析

发掘玉米抗病种质资源,克隆抗病基因并解析玉米抗病机制,是玉米抗病性品种改良的基础。类病斑突变体(Lesion mimic mutant,Lmm)是一类在没有病原菌侵染或其他外界刺激情况下,表现出类似病害所致自发性坏死斑的突变体,是研究植物抗病机制的重要材料。对类病斑突变体Lmm18进行表型鉴定和基因初定位。该突变体首先在叶尖部表现类病斑坏死表型,坏死斑随着生长沿叶脉逐渐扩展增多,最后遍及整个叶片。通过二氨基联苯胺(3,3’-diaminobenzidine,DAB)染色,发现Lmm18中过氧化氢含量相较于野生型明显增多。此外,抗病标志基因PATHOGENESIS-RELATED 1(PR1)和PR5在Lmm18中显著上调,表明该突变体启动了抗病防御反应。遗传分析表明,该性状由显性单基因控制。利用B73与Lmm18杂交构建的F_(2)群体进行BSR-Seq(Bulked Segregant RNA-Sequencing)分析及连锁标记定位,将LMM18基因初步定位到2号染色体1.23 Mb的区间内,该研究为后续克隆该基因并解析其介导的抗病防御调控机制奠定了基础。

万寿菊舌状花花冠裂片突变体的形态鉴定及连锁标记开发

万寿菊(Tagetes erecta)是菊科万寿菊属重要的观赏花卉,其舌状花花冠边缘的类型有平滑(smooth)、波浪(undulate)及不同程度的缺刻(incision)等。以第1轮小花花冠筒边缘五裂且雄蕊发育正常的万寿菊突变体JH和舌状花花冠边缘平滑且雄蕊败育的万寿菊自交系S5为亲本构建F_(2)代分离群体。遗传分析表明,JH突变性状由显性单基因控制,将其命名为Telf。组织学和细胞学观察发现JH第1轮小花为舌状花管瓣化,其花冠筒顶部具有5个裂片,中下部融合呈管状,且花药和花粉粒发育恢复正常。利用BSR-seq和比较基因组学方法,将控制舌状花花冠裂片形成的基因Telf定位于37003-SCAR标记和34032-CAPS标记之间,2个标记距Telf的遗传距离分别为3.684 cM和3.517 cM。该研究为后续精细定位目的基因Telf奠定了基础,也为万寿菊分子标记开发提供了新方法。

莴苣叶裂性状的遗传定位

以叶片全缘(entire)莴苣PI491070和叶裂(lobed)莴苣PI536760为亲本构建F_2代分离群体,F_2代性状分离调查结果显示叶裂性状为单基因显性性状。利用BSR-seq方法对莴苣叶裂性状进行快速遗传定位,将控制叶裂性状的基因定位在3号染色体的60~140 Mb之间。通过1 159株F_2群体的隐性单株进行分析最终将目的基因定位在116.24~118.15 Mb之间,物理距离大约为1.91 Mb。该区域包括24个候选基因,其中基因LG3316063编码锌指蛋白,在两亲本中有1个碱基的差异并导致了氨基酸的改变。从莴苣资源库中随机挑选5种叶裂植株检测该基因差异SNP位点都为G,7种无叶裂植株该基因SNP都为T,推测该基因可能是控制叶裂形成的候选基因。

涝渍胁迫下玉米不定根产生候选基因的发掘

不定根产生是玉米对涝渍胁迫适应的形态之一,本研究拟发掘调控玉米不定根产生的候选基因。本研究对400份玉米自交系进行涝渍处理,发现自交系T1162W在涝渍胁迫下产生大量的不定根,而自交系RO421W不定根数量很少。以T1162W、RO421W为亲本构建F2分离群体。从F2群体中,选择不定根大量产生和无不定根的单株,分别组成不定根产生池和不定根不产生池,并对2个混合池进行BSR-seq分析。结果发现,在第7染色体39 Mb区段,发现1个与玉米不定根产生关联的SNP。该QTL位点的发现,将为揭示玉米不定根的形成积累了生物学知识,同时为玉米耐渍性遗传改良提供新的基因资源。